How to Adjust a Centrifugal Clutch

A Centrifugal Clutch Showing the Adjuster Screw

Centrifugal clutches are mostly found on small mopeds, power tools, dirt bikes and go-karts. If the clutch is slipping when you kick or pull start the engine, or the clutch is noisy or feels like it is sticking when you are switching gears or increasing the speed of the engine, then the clutch needs to be adjusted. Adjusting a centrifugal clutch is an easy and quick process. Once you have done it, keep a set of the tools required so you can adjust your clutch wherever you are.

Things You'll Need

• Box wrench
• Flathead screwdriver

Instructions

1. Locate the clutch on your engine (consult your owner's manual if necessary). If there is a cover over the clutch, remove it.

2. Select a box wrench that snugly fits the large locknut protruding from the center of the clutch case. Loosen the nut, but do not remove it.

3. Using the flathead screwdriver, turn the adjuster screw located in the center of the locknut clockwise one turn.

4. Slowly turn the adjuster screw counterclockwise until a slight resistance can be felt. Stop turning the screw. Turn the screw very slightly clockwise, no more than an 1/8 to ¼ of a turn. Hold the screw steady with the screwdriver and hand tighten the locknut.

5. Take the screwdriver from the adjuster screw and put the box wrench on the locknut; before you tighten the nut, use the flathead screwdriver to hold the adjusting screw in place. Tighten the locknut slowly, making sure there is no change in the adjusting screw.

6. Place the cover to the clutch back on the engine, and test drive the vehicle or test run the engine of the tool.

Tips & Warnings

• Your centrifugal clutch may have a different type of adjuster screw--such as a hex key screw--than is typically found on small engines. Check your owner's manual for the right tool to have for adjusting the screw.

• Make sure that you test drive the vehicle or use the tool long enough to move it through all its gears and speeds so you can determine if the centrifugal clutch is adequately adjusted.

Resources

• Read this Article in Spanish
• History and Applications of Centrifugal Clutches
• How a Centrifugal Clutch Works